I have been using skimmer socks for a few years now and they work great. I usually have to clean them out weekly. I decided to try knee highs to see what the difference is. I put a Knee High on my skimmer basket over 2 weeks ago and it has not caught ANYTHING in it! I put a sock on the basket this morning and there is already stuff collected in it this evening. My conclusion is that Knee Highs, while cheaper, don't work anywhere near as well as skimmer socks do!